How to Fill Holes in Walls

Choosing the Right Filler

For small holes and cracks up to 5mm: ready-mixed filler like Polyfilla is ideal. For medium holes up to 20mm: use a powder filler mixed to a firm consistency. For large holes: use a specialist deep repair filler or patch with plasterboard and skim.

Filling Small Nail Holes

Press ready-mixed filler firmly into the hole using a flexible filling knife or your finger. Overfill slightly, allow to dry completely (1-4 hours), then sand flush with 120-grit sandpaper. Prime before painting.

Filling Cracks in Plaster

Use a screwdriver or filling knife to rake out any loose material from the crack first. Apply flexible decorator caulk to hairline cracks. For larger cracks, use filler applied in thin layers, allowing each to dry before the next.

Filling Medium Holes

Dampen the area first to improve adhesion. Apply filler in layers no more than 10mm deep at a time. Allow each layer to dry fully before adding the next. Overfill slightly and sand back flush when completely dry.

Patching Large Holes in Plasterboard

Cut the damaged area into a neat square. Fix backing strips inside the hole, screw a plasterboard patch in place, fill the joints with jointing compound, tape with fibreglass tape, and skim smooth.

Priming Before Painting

Filler is porous and will show through paint as a dull patch if not primed. Always apply a coat of general purpose primer or diluted emulsion over filled areas before painting.